Ultra high frequency electron discharge device



Oct. 12, 1948.

c. H. FOULKES 2,451,328

ULTRA HIGH FREQUENCY ELECTRON DISCHARGE DEVICE File d Sept. 9, 1942 3 Sheets-Sheet 1 I //v1//vr'0,?

, L C. H. FOULKES 7 8y M Jimmy A ram/5y Oct. 12, 1948. I c, FQULKES 2,451,328

ULTRA HIGH FREQUENCY ELECTRON DISCHARGE DEVICE Filed Sept. 9. 1942 SSheets-Sheet 2 I H H64. %j?

CH. FOUL/(E5 OCL IZ, 1948. c FOULKES 2,451,328

ULTRA HIGH FREQUENCY ELECTRON DISCHARGE DEVICE' Filed Sept. 9. 1942 v 3 Sheets-Sheet 3 CH, OULKES A 7'7'0RA/Ey Patented Oct. 12, 1948 Urn-RA HIGH FREQUENCY- ELECTRON 4 DISCHABGEDEYICE; c

' Christopher HenPyFOulkes,Eondon W2C. 2-;En-gland, assl'gnon to Standard Telephones and Cables Limited, company-- London; England; a British.)

Application September 9, 1942', Seria'l' No; 4s7795 In-Great Britain February14g1-941 Sectiond; Public Law 69o;;Aiigi1sts,; 194e Patent expires February- 14; 1961 r 'lhisinvention: relates, to, electrons discharge, de-

vicesand more particularly tQsuchdeVices of the a. .simp'leconstruction. of such device in which.

the heat generated. in: the, ,resonator is readily dissipated,

According toone aspect of the invention a resonatonfor an ultra high. frequency electron discharge valve comprises an inner and an outer conductor in which-,thexouterconductor consists of two or more channel-shaped sections welded or riveted-together to form a tube.

According to another aspect of the invention in a coaxial resonator for electron velocity modulated valve the outer conductor comprises, two channeligshaped sections preferably of semii cylingdrical shape provided-with integralifins sogshaped and-located that when the" sectionspare rivetedor welded together thefins bound the longitudinal edges of a' pair-of diametrically-located;slotsgin the wall of the-resonator; I

"Qne-'embodiment of the manner in Whichthe invention is carried out willbe described-with reference to an electron velocity-modulated'device of the kind: described in United States application No. 367,401 of November 2'7, 1940 now Patent.No. 2;320;, 860 granted lunel 1943 in. which thenhollowiresonator comprises ashort lengthof coaxial line.

In the accompanying drawings:

Figure 1 shows in perspective view a half-' section of an outer conductor for a resonator;

Figure 2 is a perspective view of a complete outer conductor formed of two such half-sections;

Figure 3 is a perspective view of an anode;

Figure 4 is a perspective view of the assembled resonator tube and its associated socket;

Figure 5 is a vertical section through the centre of assembly and.

Figure 6 is a plan of the base at a section taken on the line 6-6 of Figure 5.

The outer tube of the resonator instead of consisting of a copper tube as in the previous practice comprises two semi-cylindrical halfsec'tions I, 2 (Fig. 2) as shown in Figure 1 formed with lugs 3 and integral fins 4. The two sections, which may be pressed from sheet metal stampings, are riveted or welded together to form a complete tube 35 as shown in Figure 2, with comm I (01. zed-27 (5) the finsll, bounding thejdiametric apertures: through which the electron beamis r firedr I An aperture Snis'provided in one section through which aloop or probe is insertedinto the interior of; the, resonator for extractin .highi-recruency; eriergm Protrudinglugsfi, .1 are-provided at each. end oithe sections I, 2 forsecuringmicainsu lators which carry the. cathode, control: grid-:and any further electrod'esl, 1 v s It will, be appreciated. that, with this construe 1-; tion-of resonator the fins A- are-integraL- itI-r the main bodyof the resonator, whereas in. the re onators-previously formedzfrom a sectionptco per tuber, they had to belseparately provided. and: attached togthepedg-es, ofithe; apertures. The: present construction affords the advantage that: heat is. more readily vconducted away fromthe,

Itjavill, moreoven. beseen' that such a resonator is provided with a slot or aperture at eachside although it.,is only t necessary to provide a slot at. oneu'side fort ingress offlthe electron stream...- Adv'antagelfis taken. of the presence-of two slots to employ atthersidetwhere the electronsemerge ;v a. curved molybdenum anode. 340i theshape shown-l imfFigure 3,. mammar oi the electrons Willa pass right through the resonator and will borne bard the anode 8, which, beingzot-molybdenum, is. ablerto dissipate heatat a 7 higher temperature than copper. Morelheat can accordingly be dissipatedfithaniwouldibe possible in the copper tube,

andr'jthe riskof distortion of; the inner or outer; conductor orboth dueto excessive heating of thefcopper is avoided.

,The anode Bii s also-provided withfa small-hole 23 through which a small proportion of the electron stream passes to a small collector electrode 24 shown in Figure 5. This electrode is used when aligning the tube with respect to the external magnetic field, the correct adjustment being when a maximum current passes right through the small hole on to the collector electrode 24.

Figures 4 and 5 show how the resonator and its associated electrodes are mounted so that its axis is parallel to the major axis of the enclosing bulb, on a base of the kind comprising a dished glass member 9, the peripheral lip of the member 9 being used to a lip on the lower end of the enclosing glass bulb 10. Contact pins II are sealed directly into the dished member 9. The inner conductor of the resonator is made up of two copper rods 30 and 3|, each having one end spread out into a head of mushroom form. The small ends of the rods support an assembly of fins 32 which defines the slot through which the electron stream is fired. The outer conductor 35 is fixed at both ends to the mushroom heads of the rods.

The resonator is mounted upon a triangular copper plate l2 by means of a copper rod 25 screwed into the head of the rod 30, the washer 26 providing the'necessary spacing. The plate I2 is spot welded to three of the base pins l I. This.

permits the resonator to be located near the base and assists in dispersing the heat which is generated. The triangular plate l2 also has cut in it three slots 27 with their lengths parallel to the respective sides as shown to enable the plate to take up any strains which may be caused by unequal expansion of the glass and copper. The anode 8, the collector plate 24, the grid 28 and the cathode '29 are mounted upon rods l3 which pass through the mica insulators l4 and I5 and through mica spacing plates I6. The remaining pins II in the base are used for connections 'to the electrodes.

A glass tube 11 is sealed into the bulb l adjacent the hole in the resonator. Conductors I8 for extracting energy extend through the tube I1 and aperture 5, into the resonator, the conductors being sealed in a pinch I9.

When the valve is plugged into its socket 20, the three pins II which support the triangular platform or plate l2 engage in holes drilled in a substantial metal spider 2| fixed to the socket. The remaining pins engage contact terminals 22 on thesocket in the usual manner. The socket 20 is provided with a central hole 33 having a keyway 34 into which the protruding metal spigot containing the sealing ofi tube of the glass bulb to extends. This spigot has a key which engages with the key-way 34 so as to ensure that the pins H make contact with the proper terminals 22 of the socket.

The invention is not limited to the precise construction described and modifications coming within the scope of the appended claims will occur to those versed in the art. For example, the outer conductor of the resonator may be built up from three or more curved sections of suitable,

shape.

What is claimed is:

1. A coaxial resonator for an electron velocity modulated discharge tube comprising an outer tubular conductor and an inner conductor coaxial therewith, said outer conductor being formed of integral channel-shaped sections secured together at their edges, said sections having inturned fins integral therewith and forming the longitudinal 4 boundaries of a pair of diametrically located slots in said outer conductor.

2. Aphollow resonator for an electron velocity modulated discharge tube comprising channelshaped sections secured together at their edges, said sections having similarly located inturned fins integral therewith and located at their edges and forming the longitudinal boundaries of a pair of diametrically located slots in said resonator.

3. An ultra high frequency discharge tube comprising a coaxial resonator formed of concentric inner and outer conductors, said outer conductor consisting of two channel-shaped sections secured together, similarly located fins on said sections forming the longitudinal boundaries of a pair of diametrically located slots in said outer conductor, and said inner conductor including rods supported from opposite ends of said outer conductor and extending to positions opposite the respective ends of said diametrically located slots and electrodes mounted adjacent saidslots. 4. An electron velocity modulated discharge tube comprising channel-shaped sections secured together at} their edges and forming the outer conductor of a coaxial resonator, said sections having similarly located inturned fins integral therewith and located at their edges and forming the longitudinal boundaries of a pairof diametrically located slots in said outer conductor, a conductor within and coaxially with said outer conductor, a cathode adjacent to one of said slots, and an anode adjacent to the other of said slots.

CHRISTOPHER HENRY FOULKES.

REFERENCES CITED UNITED STATES PATENTS Great Britain Feb. 24, 1942 

